Halo effect for a box, how to?

Troubleshooting effects
1

Hi guys,



I searched the forum, but I couldn’t find exactly what I was looking for… hopefully someone can help me out.

I am trying to create a halo effect around a box as shown in the image below.







I tried 3 approaches but I failed with each one.

  1. I tried using bloom, which worked fine, but it seems to be quite expensive. It also affected all other objects in my scene. What is the way to turn off bloom for some objects? Render the objects with dark texture? I couldn't get it.
  2. I also tried using particles but couldn't get them to surround the box as I wanted.

particles.setGeometry((Geometry)box);

???
How can I get the particles to just surround the box and stay with it when it moves. I just want static particles around the box and apply texture to them and hopefully this will look like a halo. I think this is possible but since I couldn't find sample code for it, I couldn't do it  :D
3. I tried using a rounded box on top of the box and apply a transparent texture to it. This worked, and it was cheap, but I couldn't get it to look like a halo, it was more like a glass case.

How should I do it? Any suggestions? I would appreciate it if someone points me in the right direction. I would prefer using particles if possible because with bloom frame rate dropped significantly, but whatever you say... Or maybe there is yet another way...

thank you very much

2

The best way is to use bloom, you need to render your box in a separate pass so that other objects are unaffected.

You can change the RTT size and bloom multipass settings so that it uses less resources, but there might be a slight quality loss.



For systems without shader support you can use a single billboarded glow quad rendered behind the box, but it wouldn't follow the silhouette of the box, especially if it's rectangular like in the image you have there.



The particle idea might work but it would require you to trace the edges of the box across the frame which might be quite difficult.

3

Bloom it is! I will play around with the settings you mentioned. Thank you for your immediate reply.

4

With particles, you might use the ability of particles to be emitted from a mesh vertices.  (See TestFireMilk)



Also, perhaps you could use a rectangular semi-transparent textured box placed around your object?